Assessing an estimate

Wow.

Can this really be true?

Addressing Detroit’s Basic Skills Crisis

Various estimates of the scale of need for basic skills services in the region convey a crisis-level order of magnitude.

• The National Institute for Literacy estimates that 47% of adults (more than 200,000 individuals) in the City of Detroit are functionally illiterate, referring to the inability of an individual to use reading, speaking, writing, and computational skills in everyday life situations.
• We also know that of the 200,000 adults who are functionally illiterate, approximately half have a high school diploma or GED, so this issue cannot be solely addressed by a focus on adult high-school completion.
• The remaining 100,000 of these functionally illiterate adults (age 25 and older) lack a high school diploma or GED, another prerequisite for employment success.

I'm not sure how this institute made this estimate.

Later, the report expands somewhat on the topic:

Generally, those adults who score at Level 1 (on a scale of 1 to 5, lowest to highest) have difficulty performing such everyday tasks as locating an intersection on a street map, reading and comprehending a short newspaper article, or calculating total costs on an order form.

It isn't clear whether their estimate was that all 47% were at "Level 1", or whether those were five levels of illiteracy (versus five levels of literacy), but no matter how you slice it, those are some astonishing claims about the literacy problem in the greater Detroit region.